The frontier lines of the constituents of matter

Abstract Looking at the chart of nuclides as presented at the URL of the International Atomic Energy Agency (IAEA) [1] – that, one supposes, contains all the known nuclides, the natural and the artificial ones – one verifies the existence of two delimiting lines admitted to be the borders of the constituents of matter. One assumes that the lighter atoms have been formed in a nucleosynthesis process within the core of certain stars while the heavier were produced during the implosion of old stars, a supernova or in the fusion of two neutron stars. Making use of the nuclear semiempirical mass formula along with the energy-time uncertainty relation of quantum mechanics, we show that the calculated border lines show an appreciable agreement with the data obtained from the Chart of Nuclides, the nuclides that are situated far away from those that define the line, or valley, of stability. We also briefly discuss, qualitatively, what is currently known about the astrophysical nucleogenesis processes of the heavier nuclei and their relation with the border lines.